1. Field of the Invention
This invention relates to vapor recovery apparatus and, more particularly, to apparatus for collecting and storing vapors which evolve as volatile fluids are transferred between transporting vehicles and a storage facility.
2. Description of the Prior Art
The transfer of large quantities of crude oil and other hydrocarbon products between oil tankers and shore facilities is invariably accompanied by the generation of large volumes of vapor. At the present time these vapors are not recovered but are vented into the atmosphere where they may form explosive pockets, thereby creating a fire and safety hazard. In addition, the loss of vapors causes shrinkage of the hydrocarbon product being transferred, which of course is expensive. These vapors also contaminate the air and contribute to the generation of "smog". Up to the present time there has been no known apparatus which is available to overcome this problem of air contamination by a large tanker being loaded or unloaded.
Vapor recovery-type fluid delivery arms have been designed for use in loading gasoline tank trucks and include a delivery head assembly with provision both for discharging gasoline into the truck and for returning gasoline vapors to storage. Some examples of the prior art delivery arms are described in the United States Pats. Nos. 3,099,297 issued July 1963 to Knight, 3,176,730 issued April 1965 to Knight, and 3,825,045 issued July 1974 to Bloomquist.
These prior art recovery-type fluid delivery arms are small and are not usable for loading or unloading large tankers as they cannot handle large quantities of fluid which must be rapidly pumped into or out of the large floating tankers. If these prior art delivery arms were increased to size needed to quickly load or unload the floating tankers the arms would be too heavy and too difficult to handle. Also, the floating tankers move up, down and sideways relative to the loading dock, so the arms would need to be redesigned to accommodate the relative movement between the tanker and the dock.